Cylinder construction for air cooled internal combustion engines



C. 5. BROWN Filed Sept. 4, 1934 INYENTOR.

Dec. 1, 1936.

CYLINDER-CONSTRUCTION FOR AIR COOLED INTERNAL COMBUSTION ENGINES MM ATTORN E Y5,

Patented Dec. 1, 1936 i r I UNITED STATES earner rice CYLINDER CONSTRUCTION FOR are ooomn) INTERNAL COMBUSTION ENGINES Charles S. Brown, Syracuse, Y.

Application September 4, 1934, Serial No. "142,627

2 Claims. (01. 123171) This invention relates to cylinder or cylinder circumferen'tially-extending heat radiating fins block construction for air cooled internal com- 2, and a body or mass 3 of metal having greater bustion engines and particularly 'to cylinders heat conductivity and a greater coefiicient of exhaving a liner surrounded by a body or mass of pension than that of the liner I, surrounding the 5 metal, as aluminum or aluminum alloy, having liner and in which the fins 2 are embedded. The greater heat conductivity and coefiicient of exmass or body 3 is also formed with external heat pansion than the metal of the liner, which is usuradiating flanges 4, preferably extending cirally a ferrous metal, and has for its object a cylcumferentially around the same. The fins 2 inder or block construction in which the lining preferably at least extend over the portion there is formed with flexible heat conducting flanges, of forming the expansion space of the cylindenio which are embedded in the outer mass or body of but not necessarily over the combustion or com 1 metal having the greater heat conductivity, so pression chamber C. As shown, the compression that a good mechanical and heat conducting or chamber is formed in the upper or outer end of v thermal joint is maintained between the body or the block in co-ntradistinction to being 'in the mass and the liner, and the outer body or mass heads, and the liner I terminates short of the 15' of metal will not loosen or break away from the upper face of the block. In this construction, liner and the fins thereof under varying degrees the head (not shown) is intended to be flat or of temperature, and hence under the different not recessed to form the compression chamber. degrees of expansion and contraction of the liner The fins 2 are flexible in order to flex and react and the outer body and mass, due to their having under varying degrees of heat when the outer difierent coefficients of expansion. mass 2 elongates and contracts faster and to a It further has for its object a cylinder block greater extent than the liner I. Owing to the consisting of a liner or liners having circumferflexibility of the fins, the body or mass 3 having entially extending heat radiating fins which terthe greater heat conductivity and coefficient of minate in thin, knife-blade-like flanges, which in expansion will not loosen or break away or deturn terminate substantially in a knife edge, the stroy the good mechanical and thermal joint flanges having gradually widening base portions between the body or mass 3 and the liner I, and joining them to the body of the liner and a mass owing to the comparatively greater mass 3, not or body of metal surrounding the liner and the only is the heat absorbed quickly from the liner fins and being of considerably greater mass than I and dissipated but also the effect of internal 30 the liner and fins. stresses, due to the different coefiicients of ex- It further has for its object either a single cylpansion of the metals of the mass 3 and liner I inder block or a multi-cylinder block embodying are relieved or distributed through a mass large the above-mentioned features. enough to stand them without straining the The invention consists in the novel features mass and without undue warping. Also, due to and in the combinations and constructions herethe thin knife edge fins, the far greater mass of inafter set forth and claimed. metal of greater coeflicient of expansion unites In describing t invention, reference is had with fins better than with relatively larger fins to the accompanying awing in which like chart and make a far better heat conducting union acters designate corresponding parts in all the than with thicker fins 40 w The fins 2 are integral with the body of the Flgure 1 w of multl'cylmder liner I and include a base portion 5 and a thin is embzoqymg g i' 2 2 F1 flange portion 6, the flange portion 6 being thin me fi 1s sec 1on2 VIEW on me and what for convenience I have called knife- Figure 3 is an enlarged fragmentary cross secm flange and.th1s flange m tum termmaftes tional view through the liner and contiguous porsharp or kmffc} edge The base pol-i101 tion of the Surrounding body or mass or metal of widens from the knife-blade flange gradually mto difierent heat conductivity the body of the liner I, thereby providing round- I have here shown my invention as embodied mg grooves 8 in the liner the grooves having 50 in a multi-cylinder engine block consisting of a rounding arcuate p In other Words, the. pair of cylinders. Obviously, the block may have gradually W e i b s 5 provide grooves 3 one or any plural number of cylinders. Thi tween the heat radiating fins. This formation cylinder block comprises a liner I, usually of contributes to the forming and maintaining of ferrous metal, as steel, having integral peripheral a good mechanical and thermal joint between the 56 body or mass 3 and the liner during the flexing of the fins.

In the cylinder block here shown, the fins 4 extend circumferentially around the entire block, and the mass or body 3 is formed with transverse air passages 9 therethrough between the two liners. It will be understood that in use the cylinders are cooled by means of an air current created in any suitable manner. The air current may be directed from the side of the block transversely thereof or longitudinally of both sides of the block. However, the creating and directing of the air current forms no part of this invention.

The cylinder block is formed by standing the liner or liners in the mold and pouring the mass or body 3 which is usually aluminumor aluminum alloy around the liners and permitting the mass to cool. Preferably, the liners are covered with a fiux, as tin, before the metal forming the mass 3 is poured, and also the liners may be preheated before the mass is poured in any suitable manner, as for instance by first pouring more metal into and through the mold than is needed for the casting, and when the liner is heated to the desired amount, as determined by the foundryman, the mold allowed to fill up and cool. The cooling may be regulated or retarded by heating the mold in any suitable manner. However, the method of forming the cylinder block of this application forms no part of my invention, and is the invention of co-pending application of Thomas A. Delaney of Syracuse, New York.

This cylinder block is particularly advantageous in that the heat generated in the use of the engine is quickly conducted away from the liner,

and further in that owing to the flexible fins and their construction, a good mechanical and thermal joint between the liner and the mass of metal having the greater heat conductivity is constantly maintained during expansion and contraction or elongation and shortening of the liner and the mass of metal.

What I claim is:

1. An air cooled internal combustion engine cylinder construction comprising a liner having thin flexible integral heat radiating fins on the periphery thereof and a body of metal having greater heat conductivity than the metal surrounding the liner and the fins thereon and in which the liner and the fins are embedded, the portions of the periphery of the liner between the flexible fins being concave providing grooves with the rounding bottoms between the flexible fins, the sides of the fins curving into the margins of the rounding bottoms of the grooves.

2. An air cooled internal combustion engine cylinder construction comprising a liner having 

